Geology, Mineral Wealth & Climate

The Geology of the Kongu country is very interesting. While in the Coimbatore district, all the rocks belong to the great gneissic series, in the Salem and Dharmapuri district, rocks belong to granite, syenite, charnockite, foliated granitic gnesis, amphibolites, ultramatic rocks- Bluish grey to dark grey coarse grained rock of the Northern Kongu.

Mineral Wealth

The mineral wealth of the Kongu country is noteworthy.
Iron ore deposits were extensive, though of low grade. The deposits were found in the districts of Chitteri, Rasipuram, Namakkal and Valliampatti areas. Further, from the Sangam verses, we can conclude that Kongu was rich in Gold deposits. It is also to be noted that two-thirds of the Roman coins were obtained from Coimbatore and its surroundings. This substantiates the belief that Kongu country was a bone of contention of the three great Tamil monarchs as well as the other great ruling powers of the South India

Climate

The climate of the Kongu country was generally more pleasant than that of the adjoining parts of Tamilnadu. The year was divided into four main seasons; the dry season from January to March, the hot season from April to May, the Monsoon season from October to December, and the pleasant months were January and February. Because of the interior location of the Kongu country, it was not directly affected by the tropical cyclonic storms and depressions of the Bay of Bengal. Kongu country occasionally received heavy downpours particularly in the parts of Coimbatore, Nilgiris, Talaimalai and the Anamalai hills.